【推荐1】Sixty-six years ago, there was one human-built object in Earth’s orbit. It was Sputnik, the world’s first satellite, launched in October 1957. Try to guess how many human-made objects are circling the planet now. Ready?

Your answer is wrong, unless you guessed 100 trillion. That’s a jaw-dropping number. It was provided by an international team of researchers writing in the journal Science. For years, this junk has formed an ever-growing mass near Earth. It’s a danger to spacecraft. The researchers are calling for a global treaty to limit the number of satellites and the amount of rubbish in space.

There are 9,000 active satellites in orbit, the scientists report. That could grow to more than 60,000 by 2030. The rest of that 100 trillion figure includes everything from used-up booster rockets and stray bolts to metal flecks and paint chips. Don’t think a paint chip is harmless. Travelling at 17,500 miles per hour, it can strike a spacecraft hard. The International Space Station is dotted with dents and holes. Astronauts often take shelter in an attached spacecraft to wait out a passing swarm of space debris (残骸). That way, if the station is severely damaged, they can escape in a hurry.

The mess we’ve made in space is like the mess we’ve made in the oceans. Think of the Great Pacific Garbage Patch. It’s a mass of floating junk twice the size of Texas. We’ve had centuries to make the ocean dirty. But it has taken just decades for us to do the same in space. That’s why the Science authors include experts in satellite technology and in ocean plastic pollution. “As a marine biologist, I never imagined writing a paper on space,” writes Heather Koldewey, who works at the Zoological Society of London. Cleaning up space, she says, has a lot in common “with the challenges of tackling environmental issues in the ocean.”

Coauthor Moriba Jah is an aerospace engineering professor at the University of Texas at Austin. “Marine debris and space debris,” he writes, “are both a human-made damage that is unavoidable.”

【推荐2】Carbon Footprint

While making visits to national parks or forest preserves, you'll often be told to leave nothing but footprints.     1     One is you physical footprint. The other is what is known as your carbon footprint.     2    

Often people consider their carbon footprint to be the result of their immediate use of fossil fuels and energy usage, like cooking with natural gas or using petrol to run their automobile.     3     This may include the fossil fuel used to transport the food that you buy at your local grocery store, or the energy used to deal with the waste produced in your household.

Taking small step to reduce your carbon footprint and saving energy is actually fairly simple.     4     It requires the burning of fossil fuels to make the bottle, transport it, and get rid of it if it's not recycled. Compared with it, in-house filtration (过滤) systems can reduce your influence and cost for water.

Unplugging appliances that are not frequently in use is another way to reduce your carbon footprint. Most of these have a standby mode(待机模式) that wastes energy even when they're not in use.     5     What is more, new energy efficient light bulbs, filters, and appliances could also help reduce your carbon footprint.

In a word, less energy used means less greenhouses gas produced. With easy steps, you are on your way to reducing the size of the carbon footprint left behind.

【推荐3】Campaigns to protect the natural world are getting increasingly ambitious. But although there is convincing evidence that protected areas prevent habitat loss, proof that they actually benefit wildlife is surprisingly scanty. Now, the first large study of its kind shows nature reserves can increase waterbird populations, but typically only if humans take an active role in their management.

To understand the impact of nature reserves, conservation scientist Hannah Wauchope decided to analyze populations of waterbird species. First, the team identified 1506 protected areas that had population data from both before and after they were created. Then, they paired each reserve with one or more control sites — a similar patch of nearby habitat — that was unprotected. This setup helped the researchers understand how the protected area influenced bird populations.

The researchers had hoped the analysis would clearly show protected areas benefit birds. However, only 27% of waterbird populations in protected areas increased after the creation of the reserve while 21% of populations were negatively impacted, compared with the control sites, after a reserve was established. A silver lining is that nearly half the studied groups neither grew nor shrank: At least those populations were stable.

To figure out what was responsible for the population gains and losses, the team analyzed multiple factors, of which the most important was whether the site was specifically managed for waterbirds. That could mean keeping rivers and lakes at the right levels for the protected species, removing invasive weeds, or installing fencing to keep out invasive predators.

“The modest success of these protected areas makes sense.” says Paul Ferraro, an environmental economist. In many policy contexts, he notes, most interventions work no better than the status quo. However, the new study’s mixed results are what good science actually looks like and we need more studies like this one.

【推荐1】Imagine that your friend is cutting the cake to share with all the guests at the birthday party. The first three guests are handed large pieces of cake, while you are handed a teeny-tiny one. How would you feel? Is this fair? Most of us have a clear sense of what is fair and what is not, but where does this come from? Scientists try to study fairness in primate species (灵长类物种) to understand how fairness came about.

Fairness often involves equal outcomes (平等的结果)

Do monkeys behave in ways that lead to equal outcomes? To find out, scientists give monkeys choices about how to share food. Scientists ask a monkey to choose between two options—to provide a piece of food just for themselves, or to provide food for another monkey nearby, as well as for themselves (Figure 1). If monkeys are trying to achieve equal outcomes, they would give food to both themselves and another. Do they? Sometimes.

The left monkey has just chosen the board to give food to himself and the neighboring monkey.	The left monkey has just chosen the board that provides food for himself only.

Whether monkeys favor equal outcomes seems to depend on the species. The species which live in groups will prefer equal outcomes, but not all the time.

What else might be influencing whether monkeys create equal outcomes? If the two monkeys are friends, one is more likely to share food with the other. It also seems that monkeys would make the equal choice when they cannot see the actual food—some scientists use pictures of food.

But wait, does effort matter?

Scientists have developed a way to test whether monkeys prefer everyone to be paid equally for doing the same work. In this study, monkeys are trained to work for food by exchanging small coins with a scientist. To determine if and how monkeys respond to unfairness, scientists have two monkeys take turns exchanging coins and give them different food—their favorite food or a less-preferred food (Figure2). If the monkey getting the less-preferred food refuses to keep exchanging coins, scientists conclude the monkeys respond to unfairness.

The monkey on the left exchanges the coin for a piece of banana. Next, the neighbor monkey will also exchange a coin, but receive a less-preferred piece of food.

The results of the study have suggested differences across monkey species. Generally, monkeys living in groups do not respond to unfairness, while other monkeys do respond to it. However, monkeys do not appear to mind if they get a better food than others.

All in all, monkeys’ sense of fairness does not seem to be as well-developed as our own. By studying their preferences for fairness and responses to unfair situations, we can learn more about how these values developed in humans. And this also helps us to better understand the natural world and how to care for animals as well.

【推荐1】When this year’s all-woman team arrived on Antarctica’s Goudier Island to run the world’s most remote post office, it was shovels they needed rather than stamps.

They’d traveled some 8,000 miles from the UK, by plane and boat, and Britain’s Royal Navy had helped them dig out their new home at the Port Lockroy scientific base, which was buried up to four meters deep under several tonnes of December snow.

It wasn’t just the frozen wastes that first struck postmaster Clare Ballantyne, who at 23 years old was the baby of the four-woman group. It was that “there’s penguins everywhere.”

More than a thousand Gentoo penguins live on this tiny island on the western side of the Antarctic peninsula (半岛), around the size of a soccer field. Since 1944, when the UK’s first permanent Antarctic base was established here, it’s also become a shelter for explorers, scientists and — in recent years — tourists.

Each year, a team is selected to run and maintain the site from November to March, or summertime in the southern hemisphere. Around 4,000 people applied for this job, but just four made the cut: Ballantyne, base leader Lucy Bruzzone, wildlife monitor Mairi Hilton and shop manager Natalie Corbett.

The job also involves counting penguins: The scientific data they gather on the Gentoos’ breeding patterns is part of a decades-long study of the colony.

When it comes to choosing candidates, “there is no recipe we can follow,” says Ballantyne. “It’s about your ability to work together as a team. Cheeriness goes a long way, being able to see the light in life and resolve problems quickly.”

Ballantyne notes that there has been “a bit of a decline in recent years in the breeding success” of the Gentoo penguins, but says “the causal connect ion is the tricky bit.” While climate change is probably “the biggest driver,” they also need to carefully examine if there’s a “human element” as well. In her opinion, Antarctica tourism has boomed significantly in the past couple of decades, but there aren’t legally enforced limits on tourism, which hopes to be a regulated industry.

【推荐2】Street pavements burst open, houses flattened, and entire villages were destroyed in what’s being described as one of the worst flood disasters to hit Western Europe in more than two centuries. As reported, more than 165 people died, while dozens of others remain missing after a record rainfall caused rivers to overflow into towns and streets across western Germany, Belgium, as well as parts of the Netherlands, Switzerland and northern France. In Liège, Belgium’s third-largest city, water from the Meuse river overflowed Thursday evening into parts of the city center, causing city officials to call for residents (居民) to evacuate the area or seek higher ground.

By the weekend, fears that a dam could burst were calmed, as the water levels in the river began to go down. But many different pieces of debris (碎片) flowing through the river from nearby villages—including parts of homes, street signs and car tires—served as a reminder that it would take weeks and months to fix the damage in the surrounding villages. This may be the worst flooding disaster our country has ever known,” said Belgian Prime Minister Alexander de Croo, who declared Monday a national day of mourning (哀悼). Additional search-and-rescue teams have been brought in from France and Italy to help locate the missing and assist with the cleanup.

In western Germany, the death rose to at least 143 people. Firefighters, meanwhile, say they carried out more than 1, 000 search-and-rescue missions, which became harder by the fact that the floods had cut power lines, disabling cellphone towers. We don’t know the number yet’ but there will be many. Germany’s interior minister, Horst Seehofer, said the country must prepare much better in the future, adding, “This is a result of climate change.”

【推荐3】The Amazon rainforest spreads across nine South American countries but most of it (60%) is in Brazil. Brazilian scientists think they might have found a way to reverse the damage caused by deforestation and turn farmland back into forest. The secret lies in ancient local knowledge of soil.

Amazonian dark earth (ADE) is a thick, black soil found deep in the Amazon rainforest, and it could help restore forests around the world. ADE is a kind of compost — a soil made from dead plants and animals. Various kinds of compost are sold in gardening centers around the world, but ADE is unique. It was created by indigenous people (the descendants of people who lived somewhere before another culture arrived and took over) from the Amazon between 2,000 and 2,500 years ago. The Amazonian people, today known as Amerindians, created ADE using charcoal from fires, animal bones, food waste and poo. It contains microbes, including bacteria that help to turn chemicals in the soil into useful nutrients that feed plants and trees.

Vast areas of the Amazon have been cut down, mostly to make way for grassland for raising cattle. Scientists are looking for a way to turn grassland back into rainforest and revive forest ecosystems. These support thousands of animal and plant species, many of them unique to the area. Forests also absorb lots of carbon dioxide, a gas that cause climate change.

To see if the Amazon’s special soil could help, the scientists grew grasses and trees in ADE, regular earth and a mixture of both. Trees grown in ADE were up to six times taller than those in regular soil. ADE takes hundreds of years to create, so the scientists can’t simply make more. Team member, Dr. Siu Mui Tsai, said that instead they want to try and “copy its characteristics”, especially its helpful microbes, and see if it could help to restore natural habitats.